pci: use sriov-device-mappings when configure sriov devices

When 'sriov-numvfs' is configured in 'auto', only the devies set in
'sriov-device-mappings' are discovered and automatically configured.

Change-Id: I1be61a19639d366d787fb92815c3a8a5c302fbda
Closes-Bug: #1818975
Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@canonical.com>

config.yaml

@@ -212,9 +212,11 @@ options:
     default: auto
     description: |
       Number of VF's to configure each PF with; by default, each SR-IOV PF will
-      be configured with the maximum number of VF's it can support. Either use
-      a single integer to apply the same VF configuration to all detected
-      SR-IOV devices or use a per-device configuration in the following format
+      be configured with the maximum number of VF's it can support. In the case
+      sriov-device-mappings is set, only the devices in the mapping are configured.
+      Either use a single integer to apply the same VF configuration to all
+      detected SR-IOV devices or use a per-device configuration in the following
+      format
       .
         <device>:<numvfs>
       .

hooks/neutron_ovs_utils.py

@@ -599,6 +599,17 @@ def configure_ovs():
     service_restart('os-charm-phy-nic-mtu')
 
 
+def _get_interfaces_from_mappings(sriov_mappings):
+    """Returns list of interfaces based on sriov-device-mappings"""
+    interfaces = []
+    if sriov_mappings:
+        # <net>:<interface>[ <net>:<interface>] configuration
+        for token in sriov_mappings.split():
+            _, interface = token.split(':')
+            interfaces.append(interface)
+    return interfaces
+
+
 def configure_sriov():
     '''Configure SR-IOV devices based on provided configuration options
 
@@ -621,13 +632,19 @@ def configure_sriov():
 
     # automatic configuration of all SR-IOV devices
     if sriov_numvfs == 'auto':
+        interfaces = _get_interfaces_from_mappings(
+            charm_config.get('sriov-device-mappings'))
         log('Configuring SR-IOV device VF functions in auto mode')
         for device in devices.pci_devices:
             if device and device.sriov:
-                log("Configuring SR-IOV device"
-                    " {} with {} VF's".format(device.interface_name,
-                                              device.sriov_totalvfs))
-                device.set_sriov_numvfs(device.sriov_totalvfs)
+                if interfaces and device.interface_name not in interfaces:
+                    log("Excluding configuration of SR-IOV device {}.".format(
+                        device.interface_name))
+                else:
+                    log("Configuring SR-IOV device"
+                        " {} with {} VF's".format(device.interface_name,
+                                                  device.sriov_totalvfs))
+                    device.set_sriov_numvfs(device.sriov_totalvfs)
     else:
         # Single int blanket configuration
         try:

unit_tests/test_neutron_ovs_utils.py

@@ -880,6 +880,24 @@ class TestNeutronOVSUtils(CharmTestCase):
         )
         self.assertTrue(self.remote_restart.called)
 
+    @patch('os.chmod')
+    def test_configure_sriov_auto_mapping(self, _os_chmod):
+        self.os_release.return_value = 'mitaka'
+        _config = {
+            'enable-sriov': True,
+            'sriov-numvfs': 'auto',
+            'sriov-device-mappings': 'net1:ens49'
+        }
+        self._configure_sriov_base(_config)
+
+        nutils.configure_sriov()
+
+        self.assertFalse(self.mock_sriov_device.set_sriov_numvfs.called)
+        self.mock_sriov_device2.set_sriov_numvfs.assert_called_with(
+            self.mock_sriov_device2.sriov_totalvfs
+        )
+        self.assertTrue(self.remote_restart.called)
+
     @patch('os.chmod')
     def test_configure_sriov_numvfs(self, _os_chmod):
         self.os_release.return_value = 'mitaka'